Hole forming apparatus



1967 M. LIBERMAN HOLE FORMING APPARATUS 6 Sheets-Sheet 1 Filed July 15, 1965 INVENTOR ATTOR M. LIBERMAN 3,357,282

HOLE FORMING APPARATUS 6 Sheets-Sheet 2 INVEN TOR ATTOFMEY Dec. 12, 1967 Filed July 15, 196

Dec. 12, 1967 Filed July 15, 1965 M. LIBERMAN HOLE FORMING APPARATUS 6 Sheets-Sheet 3 Dec. 12, 1967 M. LIBERMAN HOLE FORMING APPARATUS Filed July 15, 1965 6 Sheets-Sheet 4 mvzmon /)7/4 70 0550114 BY J I ATTOR Dec. 12, 1967 M. LIBERMAN 3,357,282

HOLE FORMING APPARATUS Filed July 15, 1965 i 6 Sheets-Sheet 5 3 Z9 64 lllllllllllflll. 79

50 I'; Jr 2% l i Mi" A A, i j INVEN Dec. 12, 1967 L|BEMAN 3,357,282

HOLE FORMING APPARATUS Filed July 15, 1965 6 Sheets-Sheet 6 INVENTOR MM MN 1 lBEEMfl/Y United States Patent Ofilice 3,357,282 Patented Dec. 12, 1967 3,357,282 HOLE FORMING APPARATUS Milton Liberman, 65 Sewane Road, East Rockaway, NY. 11518 Filed July 15, 1965, Ser. No. 472,168 11 Claims. (CI. 77-77) ABSTRACT OF THE DISCLOSURE A precision hole cutting device for ceiling tiles and the like wherein the cutting blade is carried by a slidable member disposed within a housing and threaded means are utilized to feed the blade into the material being cut as the device is rotated about a center.

This invention relates to hole forming apparatus and more specifically to a novel and improved method and apparatus for precisely forming holes in sheet materials such as ceiling tiles and boards of fibrous materials, plastics, wood and the like.

While the invention is useful in a variety of applica tions, it is particularly useful in the formation of holes in fibrous ceiling tile and board for the installation of recessed lighting fixtures. Heretofore, recessed lighting fixtures were provided with rims acting as escutcheons to cover the edges of the holes formed in the ceiling tile to accept the fixtures. This was necessary since known procedures for forming holes in ceiling tile and particularly fibrous materials produce a relatively rough, raw edge about the hole. Such conventional procedures include the use of rasps, keyhole saws and the like.

This invention has as one of its objects a novel and improved system for forming holes in ceiling tile and the like that will provide a sharp smooth corner between the wall of the hole and the outer surface of the tile and will not pull or fray the material being cut. Through the utilization of the novel and improved method and apparatus in accordance with the invention, holes can be readily formed in ceiling tile wherein the wall of the hole can either be at 90 with the surface of the tile or the holes may be tapered so that the wall of the hole forms either an obtuse or acute angle with the front surface of the tile.

Another object of the invention resides in a novel and .improved apparatus for forming clean holes in ceiling tiles of fibrous and other materials.

Still another object of the invention resides in the provision of a novel and improved method for forming holes in ceiling tiles of fibrous and other materials.

The above and other objects of the invention will become more apparent from the following description and accompanying drawings forming part of this application.

In the drawings:

FIGURE 1 is a perspective view of a hole formed in a tile of fibrous material.

FIGURES 2a through c are cross-sectional views of holes formed in slabs of material to illustrate the several types of holes that can be formed.

FIGURE 3 is a perspective view of one embodiment of apparatus in accordance with the invention.

FIGURE 4 is a top view in partial section of the appa ratus shown in FIGURE 3.

FIGURE 5 is a side elevational view of the apparatus shown in FIGURE 3.

FIGURE 6 is an exploded perspective view showing the assembly of the cutting apparatus used in the embodiment of the invention shown in FIGURES 1 through 5.

FIGURE 7 is a cross-sectional view of FIGURE 4 taken along the line 7-7 thereof.

FIGURE 8 is a cross-sectional view of FIGURE 7 taken along the line 8-8 thereof.

FIGURE 9 is' a cross-sectional view of FIGURES 5 and 7 taken along the line 9-9 thereof.

FIGURE 10 is a cross-sectional View of FIGURES 5 and 7 taken along the line 1il-l0 thereof.

FIGURE 11 is a cross-sectional view of FIGURE 4 taken along the line 1111 thereof.

FIGURE 12 is a cross-sectional view of FIGURE 11 taken along the line 1212 thereof.

FIGURE 13 is a plan view of a modified structure of radial arm that may be utilized with the embodiment of the invention shown in FIGURES 1 through 5.

FIGURES 14 and 15 are cross-sectional views of FIG URE 13 taken along the lines 14-14 and 15-15 thereof.

FIGURE 16 is a side elevational view of a modified embodiment of the invention.

FIGURE 17 is a perspective view of a fragmentary portion of the radial arm of the embodiment of the invention as shown in FIGURE 16.

FIGURE 18 is a side elevational view of still another embodiment of the invention.

FIGURE 19 is an exploded perspective view of a fragmentary portion of the radial arm shown in FIGURE 18 and illustrating the means for adjusting the position of the cutting mechanism.

FIGURE 20 is a cross-sectional view of apparatus in accordance with the invention showing one form of stabilizing means to hold the cutting assembly in precise relationship with the material being cut.

FIGURE 21 is a cross-sectional view of a modified stabilizing assembly.

FIGURE 22 is a bottom view of the stabilizing assembly of FIGURE 21 taken along the line 2222 thereof.

As pointed out above, the customary mode for forming holes in tiles and wall board of fibrous and other materials has involved the utilization of sabre saws, keyhole saws, rasps, and the like, and it has been found that such devices leave relatively rough edges. When such holes are intended for receiving lighting fixtures or the like, it is necessary to provide a rim of sufficient width to cover the frayed or uneven edge of the hole. With this invention, it is possible for instance to form a precise hole even in the softest of materials so that lighting fixtures can be installed in the openings without the need for a peripheral r rim. This provides for a much more attractive and desirable lighting fixture installation. Furthermore, with this invention, the holes may be formed at the site of the installation quickly and easily and of a diameter that will exactly accommodate the lighting fixtures to be installed. In addition, it is possible to taper the wall of the opening in either direction with reference to the normal surface of the tile or other board and still obtain a smooth, clean edge.

By way of an example, FIGURE 1 illustrates a tile generally denoted by the numeral 10 having an opening 11 therein formed by the apparatus in accordance with the invention. Both the front edge 12 and the rear edge 13 are smooth, clean edges and the wall portion between the edges 12 and 13 is free of loose or frayed fibers even when the tile is formed of conventional fibrous materials.

As will be shown, the holes may be formed in material having configurations shown generally in FIGURES 2a through c. In FIGURE 2a, the wall 14 of the hole is generally perpendicular to the front surface of the tile 10. In FIGURE 2b, the wall 15 is tapered outwardly, while in FIGURE 20, the wall 16 is tapered inwardly. As will become apparent as the description proceeds, the particular angles at which the walls 15 and 16 are formed can be adjusted over a relatively wide range.

One embodiment of hole forming apparatus in accordance with the invention is shown in FIGURES 1 through 12 and comprises a central pedestal 20 having four peripherally disposed pins 21 and a central pin 22 that is some 3 what longer than the peripheral pins 21. When the pedestal is placed on a tile or board such as the board It) in -which the hole 11 is to be formed, the center of the hole is marked on the board 16 and the elongated central pin is then aligned with the center. The pedestal 20 is then pushed downwardly so that the pins 21 fully engage the board 1% and permit the pedestal 2%) to engage the surface of the board. For this purpose, it may be desirable to place a second board Iii beneath the board to accommodate the pins unless the board 10 has sutiicient thickness.

The pedestal carries an upwardly extending stud 23, as will be seen more clearly in FIGURES 11 and 12, which is pressed into a central hole 24 in the pedestal. In order to have a flush surface on the bottom of the pedestal, the stud 23 has a flange 25 which fits into a cooperating recess 26 in the underside of the pedestal. The center of the stud has a threaded opening 27 to receive the central pin 22. The upper end of the stud 23 has a threaded section 28 of reduced diameter to receive a knob 29 as will be described.

The pedestal 20 supports a rotatable carrier member 39 having a central opening 31 which fits the central stud 23 and an elongated slot 32 to slidably accommodate the radial arm 33. In the instant embodiment of the invention, the arm 33 has a plurality of spaced openings 34 each having a diameter to slidably engage the stud 23. Inasmuch as the instant embodiment of the invention is intended for use in cutting openings to accommodate recessed lighting fixtures, the utilization of holes 34 facilitates setting the cutter for specific fixtures. The top surface 33' of the arm 33 is coordinated with the stud 23 so that it lies slightly below the shoulder 23 on the stud. In this way, when the knob 29 is threaded onto the stud, adequate clearance between the bottom edge of the knob and the arm 33 will be provided for free rotation of the latter.

The cutting means generally denoted by the numeral 35 is shown more clearly in FIGURE 4, and the outer end of the arm 33 is provided with a recess 36 to accommodate this cutting assembly. More specifically, the cutting assembly comprises an elongated housing 37 having a channel 38 extending from the lower edge to a point spaced from the top. The top 39 of the housing 37 has a central threaded opening 40 for threadably receiving an elongated shaft 41. The shaft 41 is threaded throughout its extent as denoted by the numeral 42, and the top end has a threaded section 43 of slightly reduced diameter. The bottom end of the shaft terminates in a cylindrical member 44 connected to the shaft by a narrow neck 45.

The lower end of the shaft 41 carries a blade holder 46 which is in the form of a rectangular block adapted to slidably engage the channel 38. The upper end of the block has a horizontal recess 47 formed in one edge thereof and having a height corresponding to the thickness of the cylindrical key 44. A second recess 48 is formed in the top of the block and intersects the recess 47. The width of the recess 48 is slightly greater than the diameter of the neck 45 on the lower end of the shaft 41. In this way, the block can be engaged with the cylindrical key 44 on the bottom of the shaft, and the shaft may then rotate relative to the block 46. One side of the block 47 has a vertically disposed recess 49 having a width equal to the width of the cutting blade 50, and this recess ex- 'tends from the bottom edge of the block to a point spaced from the slot 47. The blade 50 is held. in place in the recess 49 by a screw 51 which extends through an opening in filler block 52 and a registering opening 53 in the blade 50 and threadably engages an opening 54 in the block 46. The filler block 52 preferably has an outwardly extending ledge 52 which engages the upper edge of the blade 5th and cooperates in locking the blade in a firm I;

position in the block 46.

The housing 37 is closed by a cover plate 55 that may be secured to the housing by any suitable means as by screws 56 which extend through openings in the cover plate 55 and threadably engage cooperating openings in the housing 37. The bottom of the housing 37 carries a guide plate 57 which is secured thereto by a screw 58. The plate 57 has an elongated slot 59 through which the cutting blade 5t) extends. The back edge 50 of the cutting blade slidably engages the root of the slot 59 and thereby provides further support for the blade 50.-

The cutting assembly 35 snugly fits the recess 36 in the outer end of the radial arm 33 and is held in place therein by a set screw 6i) which threadably engages an opening 61 in the outer end of the radial arm 33, as may be viewed in FIGURE 6, and extends into a shallow recess 62 in the housing 37 as may be observed more clearly in FIGURES 8 and 9. When the cutting assembly 35 is in place in the outer end of the radial arm, a block 63 is inserted between the ends of the arms 64 and 65 resulting from the formation of the recess 36 and the block 63 is held in place by screws 66 and pins 67. Insertion of the block 63 strengthens the arms 64 and 65 and enables the cutting assembly 35 to be held firmly in position. A knob 68 threadably engages the top end 43 of the threaded shaft 41 and is preferably locked in position on the shaft 41.

With the apparatus as described and in position on a board 19' in which a hole is to be formed as shown in FIG= URES 3 and 5, the knob 68 is rotated to bring the cutting edge of the blade St) into contact with the surface of the board. Thereafter, the cutting assembly 35 is rotated by holding the knob 68 firmly. If necessary, pressure can be applied to the knob 29 to firmly hold the device in posi tion. As the cutting assembly 35 and the arm 33 are re tated, relative rotation will occur between the housing 37 and the threaded shaft 41, and this action feeds the blade 56 downwardly at a rate proportional to the rate of rotation. This action continues until the blade extends through the board 10 to complete the formation of the hole. Rotation of the assembly is shown in FIGURE 4;

The body of the cutting edge C on the blade 50 is preferably positioned centrally of the width of the blade as shown more clearly in FIGURES 5 and 6. The plane of the cutting edge is preferably disposed at an angle of about 45 with the longitudinal axis of the blade 50 though this angle may be varied over a relatively wide range. With the cutting edge C disposed centrally of the blade, the blade will feed through the material being out without abrading or adversely affecting the resultant inner edge of the hole and will feed straight through the material. In some cases, it may be desirable to put a very slight taper in one direction or the other on a hole such as that shown in FIGURE 2a. Should it be desired to slightly increase the diameter of the hole as the blade proceeds through it, the cutting edge C would be formed on the outer edge of the blade as it would cut through the material. Should it be desired to taper the hole slightly inwardly, then the cutting edge may be placed on the inner edge of the cutting blade. Even with the cutting edge C in the center of the blade or at the inner edge, it has been found that there is no abrading of the hole edge notwithstanding the fact that a substantial thickness of the blade body will be disposed between the vertical plane containing the cutting edge and the plane of the hole being cut. This obtains notwithstanding the utilization of blades having thicknesses of the order of .030 inch to .050 inch.

A modified form of the invention is shown in FIG- URES 13 through 15, and corresponding elements of these figures and those illustrating the embodiment of the invention previously described are denoted by like numerals. In this embodiment of the invention, the radial arm, which is denoted by the numeral 70, has an elongated slot 71 therein in place of the holes 34 in the arm 33. The arm 70 is held in position by a screw 72 which extends through the slot at a point spaced from the central stud 23 and threadably engages the carrier 30. Thus, the radial opening of a selected diameter.

As pointed out above, tapered openings can be formed in a board or title as shown in FIGURES 2b and 2c. The opening shown in FIGURE 2b may be formed by the form of the invention shown generally in FIGURES 16 and 17. The structure is identical in every respect to that shown in the embodiment of the invention illustrated in FIGURES 1 through 12 except for the outer end of the radial arm 33 which carries the cutting assembly 35. The radial arm in FIGURES 16 and 17 is denoted by the numeral 73 and may either have a plurality of openings 34 as shown in FIGURE 11 or an elongated slot 71 as shown in FIGURE 13. The outer end of the radial arm has an inclined cutting assembly receiving opening 74 which in the illustrated embodiment of the invention is disposed at approximately 45 with reference to the surface of the pedestal 20. The assembly 35 is held therein by a suitable set screw 75, and if desired, a support may be interposed between the legs 76 and 77 in order to prevent their separation in the same manner as illustrated in FIGURES 1 through 10. The operation of the device as shown in FIG- URES l6 and 17 is identical to that previously described in that the blade is gradually fed through the material as the device is rotated and thus produces a clean opening free of ragged or frayed edges.

From the foregoing description of FIGURES 16 and 17, it is quite evident that the channel 74 in the end of the radial arm 73 can be positioned at any desired angle relative to the surface of the pedestal 29.

A universal device is shown in FIGURES 18 and 19 which provides for the positioning of the cutting assembly 35 at any desired angle. In this embodiment of the invention, the radial arm denoted by the number 78 is bifurcated to provide a pair of outwardly extending arms '79 and 80. Each arm is provided with a semi-circular channel 81 and 32, respectively. These channels receive a rocker 83 having semicircular guides or flanges 84 and 85 on each side thereof. These guides 84 and 85 are slidably received by the channels 81 and 82 so that the rocker may be positioned at any desired angle. The central portion of the rocker has a rectangular opening 86 to receive the cutting assembly 35, the latter being held securely in the rocker by a set screw 87. When the rocker and cutting assembly are in place as shown in FIGURE 18, they can be held at a selected angle by a set screw 88 threadably engaging an opening extending through the leg 79 and bearing against the adjoining side of the rocker 83. In this way, it is evident that any desired taper may be formed on the side walls of the opening to be formed in the tile or board 10.

In certain cases, it may be desirable to provide stabilizing means for the forms of the invention heretofore described in order to maintain the cutting blade 50 at a precise angle with the work. One form of stabilizing means is shown in FIGURE 20 and is used with the form of the invention shown generally in FIGURES 3 through 12. The stabilizing means is generally denoted by the numeral 90' and comprises a relatively fiat disk 91 having an upwardly extending peripheral flange 92. The plate or disk 91 has openings therein through which the pins 21 and 22 extend which automatically centers the plate beneath the cutting apparatus. The peripheral flange 92 is made of a height sufficient to engage the arm 33 and maintain it in parallel relationship with the material being cut so that the edge of the formed hole will be cleanly cut at the selected angle.

A modified form of stabilizing means is shown in FIG- URES 21 and 22. In this form of the invention, a shoe or slider 93 is carried by a downwardly extending post 94 secured to the underside of the arm 33 by means of a screw 95 or other suitable fastening means. The leading edge 93 of the shoe 93 is bent upwardly to insure smooth movement of the shoe over the workpiece 10. The length of the post 94 is adjusted so that the shoe 93 will engage the surface of the workpiece 10 and thereby hold the arm 33 in a position parallel to the workpiece as it is rotated to form the opening.

While only certain embodiments of the inventionhave been illustrated and described, it isapparent that alterations, modifications and changes may be made without departing from the true scope and spirit thereof as defined by the appended claims.

What is claimed is:

1. Apparatus for forming holes in materials such. as ceiling tile and the like comprising a central pedestal, an arm pivotally secured centrally of the pedestal for rotation in the plane thereof, and a cutting assembly carried by said arm, said assembly including a housing, a slidable blade carrier within said housing, a blade secured to said blade carrier and extending from said housing, a threaded rod threadably engaging said housing and rotatably secured to said blade carrier, said rod extending from said housing and having a knob fixedly secured to the outer end thereof, said knob being grasped by the operator to rotate said arm thereby gradually feeding said blade outwardly of said housing as the arm is rotated.

2. Apparatus according to claim 1 including support means between said arm and said material to stabilize said arm during rotation thereof.

3. Apparatus according to claim 1 wherein said knife blade is of rectangular cross section and has an inclined cutting edge on the outer end thereof positioned centrally of the thickness of the blade body.

4. Apparatus for forming holes in sheet materials comprising a central pedestal, means carried by said pedestal for positioning it centrally of the hole to be formed, an arm pivotally secured to said pedestal and extending outwardly thereform, a cutting assembly carried at the outer end of said arm and extending upwardly therefrom, an annular supporting plate underlying said pedestal and having a diameter smaller than the hole to be cut, and upwardly extending flanges on said plate for slidably engaging and stabilizing said arm in a plane parallel to said sheet material, said cutting assembly including a cutting blade extending downwardly therefrom and means for gradually feeding said blade outwardly of said assembly an into said material as said arm is rotated about the pedestal, said cutting assembly including a housing, a blade carrier slidably retained in said housing, means securing the inner end of said blade to said carrier, a threaded rod threadably engaging and extending from said housing, means pivoting the inner end of said rod to said carrier and a knob fixed to the outer end of said rod for rotation of said rod as the arm is rotated about said pedestal.

5. Apparatus according to claim 4 wherein the outer end of said blade includes an inclined cutting edge positioned centrally of the blade body.

6. Apparatus for forming holes in sheet materials comprising a central pedestal, means carried by said pedestal and extending downwardly therefrom for positioning it on said material and centrally of the hole to be formed, a carrier having a diametral slot pivotally secured to said pedestal, an arm in the carrier slot and extending outwardly therefrom, a cutting assembly carried at the outer end of said arm and extending upwardly therefrom, said assembly including a housing, a slidable blade carrier within said housing, a blade secured to said blade carrier and extending from said housing, a threaded rod threadably engaging said housing and rotatably secured to said blade carrier, said rod extending from said housing and having a knob fixedly secured to the outer end thereof, said knob being grasped by the operator to rotate said arm thereby gradually feeding said blade outwardly of said housing as the arm is rotated, and arm stabilizing means between said arm carrier and said cutting assembly, the last said means cooperating with said pedestal and arm carrier to hold the arm parallel to the surface of the material during the cutting operation.

7. Apparatus according to claim 6 wherein said stabilz- *ing means comprises a shoe-like slider secured in spaced relationship to the underside of said arm and at a point between said pedestal and said cutting assembly.

8. Apparatus for forming holes in the sheet materials comprising a central pedestal, means carried by said pedestal and extending downwardly therefrom for positioning it on said material and centrally of the hole to be formed, a carrier having a diametral slot pivotally secured to said pedestal, an arm in the carrier slot and extending outwardly therefrom, a cutting assembly carried at the cutter end of said arm and extending upwardly therefrom, said assembly including a housing, a slidable blade carrier within said housing, a blade secured to said blade carrier and extending from said housing, said blade having an inclined cutting edge on the lower end thereof with said edge being disposed in a plane parallel with and positioned centrally of the sides of said blade, a threaded rod threadably engaging said housing and rotatably secured to said blade carrier, said rod extending from said housing and having a knob fixedly secured to the outer end thereof, said knob being grasped by the operator to rotate said arm thereby gradually feeding said blade outwardly of said housing as the arm is rotated, and arm stabilizing means between said arm carrier and said cutting assembly, the last said means cooperating with said pedestal and arm carrier to hold the arm parallel to the surface of the material during the cutting operation.

9. Apparatus according to claim 8 wherein said stabilizing means comprises a disk underlying said pedestal and having a peripheral flange extending upwardly therefrom and in contact with said arm.

10. Apparatus according to claim 8 wherein said stabilizing means comprises a shoe-like slider secured in spaced relationship to the underside of said arm and at a point between said pedestal and said cutting assembly.

11. Apparatus according to claim 8 wherein said cutting assembly is pivotably carried by said arm and tiltable in the plane of the axis of rotation of said arm, said arm further includes means securing said assembly in a selected position.

References Cited UNITED STATES PATENTS 884,036 4/ 1908 Packard 145-121 945,009 12/ 1909 Rose 7777 1,545,632 7/1925 Basmaison 145-121 20 1,966,962 7/ 1934 Horhorouny 77-77 FOREIGN PATENTS 1904 Great Britain. 1906- Great Britain. 

1. APPARATUS FOR FORMING HOLES IN MATERIAL SUCH AS CEILING TILE AND THE LIKE COMPRISING A CENTRAL PEDESTAL, AN ARM PIVOTALLY SECURED CENTRALLY OF THE PEDESTAL FOR ROTATION IN THE PLANE THEREOF, AND A CUTTING ASSEMBLY CARRIED BY SAID ARM, SAID ASSEMBLY INCLUDING A HOUSING, A SLIDABLE BLADE CARRIER WITHIN SAID HOUSING, A BLADE SECURED TO SAID BLADE CARRIER AND EXTENDING FROM SAID HOUSING, A THREADED ROD THEREBY ENGAGING SAID HOUSING AND ROTATABLY SECURED TO SAID BLADE CARRIER, SAID ROD EXTENDING FROM SAID 